SVXLink Setup on Pi4 with NAT64/DNS64 if possible

SVXLink Setup from Scratch on a Pi4

# RPi4 install mit Bookworm latest                                                                                                                     

URLs: 
  * https://wiki.fm-funknetz.de/doku.php?id=fm-funknetz:technik:shari-sa818
  * https://fm-funknetz.de/svxlink-installieren/
  * https://www.vr2xkp.org/2015/09/20/echolink-2015-svxlink-14-08-1-as-echolink-node/
  * https://fm-funknetz.de/wichtige-infos-zur-svxlink-version-1-8-99-2/

## add in /boot/config.txt
  ```
  max_usb_current=1
  dtoverlay=audio=off
  ```

## add to rc.local
  ```
  vcgencmd display_power 0
  ```

## /etc/udev/rules.d/90-cm108.rules
  ```
  # block pulseaudio using the soundcard for SVXLINK
  ATTRS{idVendor}=="0d8c", ENV{PULSE_IGNORE}="1"
  # create a symlink /dev/hidrawX to /dev/cm108gpio
  SUBSYSTEM=="hidraw", ATTRS{idVendor}=="0d8c", SYMLINK+="cm108gpio", MODE="0666"
  ```

## install svxlink, per default disabled in systemd
  See extras below.

## install audio files
  * https://github.com/sm0svx/svxlink-sounds-en_US-heather/releases

  Bookworm uses 19.09 --> 
  ```
  cd /root
  wget https://github.com/sm0svx/svxlink-sounds-en_US-heather/releases/download/19.09/svxlink-sounds-en_US-heather-16k-19.09.tar.bz2
  mkdir -p /usr/share/svxlink/sounds
  tar xf svxlink-sounds-en_US-heather-16k-19.09.tar.bz2 -C /usr/share/svxlink/sounds
  ln -s en_US-heather-16k /usr/share/svxlink/sounds/en_US
  ```
 
# adapt svx link config
 https://wiki.fm-funknetz.de/doku.php?id=fm-funknetz:technik:shari-sa818#notwendige_anpassungen_der_svxlinkconf


# Extras

## Systemd tunings
  ``` 
  # /etc/systemd/system/svxlink.service.d/override.conf 
  [Service]
  ExecStartPre=/bin/sh -xec "mkdir -p /run/svxlink; chown -R svxlink: /run/svxlink"
  ExecStartPre=/bin/sh -xec "alsactl restore -f /etc/svxlink/cm108b.alsactl"
  ```

## SvxLink aus Debian Bookworm installieren
  ```
  apt-get install -y svxlink-calibration-tools svxlink-gpio svxlink-server lame opus-tools speex
  systemctl disable svxlink
```

### install audio files
  * https://github.com/sm0svx/svxlink-sounds-en_US-heather/releases

  Bookworm uses 19.09 --> 
```
  cd /root
  wget https://github.com/sm0svx/svxlink-sounds-en_US-heather/releases/download/19.09/svxlink-sounds-en_US-heather-16k-19.09.tar.bz2
  mkdir -p /usr/share/svxlink/sounds
  tar xf svxlink-sounds-en_US-heather-16k-19.09.tar.bz2 -C /usr/share/svxlink/sounds
  ln -s en_US-heather-16k /usr/share/svxlink/sounds/en_US
```

## SvxLink manuel kompilieren

```
  groupadd svxlink
  useradd -g svxlink -d /etc/svxlink svxlink
  usermod -aG audio,nogroup,svxlink,plugdev svxlink
  usermod -aG gpio svxlink
```
```
apt-get install -y \
  g++ make libsigc++-2.0-dev \
  libgsm1-dev libpopt-dev tcl-dev \
  libgcrypt-dev libspeex-dev \
  i2c-tools libi2c-dev \
  libasound2-dev alsa-utils \
  git cmake \
  libjsoncpp-dev libopus-dev \
  gpiod libgpiod-dev librtlsdr-dev alsa-utils vorbis-tools curl libcurl4-openssl-dev rtl-sdr libjsoncpp-dev \
  rtl-sdr libcurl4-openssl-dev libogg-dev librtlsdr-dev groff doxygen graphviz python3-serial libssl-dev \
  #
```
```
  git clone https://github.com/sm0svx/svxlink svxlink-git
  mkdir svxlink-git/src/build
  cd svxlink-git/src/build
  # NOTE: https://fm-funknetz.de/wichtige-infos-zur-svxlink-version-1-8-99-2/
  git co -b 1.8.99.2-pre ece6514875c3d36d2eb2901af3ffdd550a1811ef
  cmake -DUSE_QT=OFF -DCMAKE_INSTALL_PREFIX=/usr -DSYSCONF_INSTALL_DIR=/etc -DLOCAL_STATE_DIR=/var -DWITH_SYSTEMD=ON ..
  make -j4
  sudo make install
  sudo ldconfig
```